For tanking, the Fleet Nebula wins out, but it is comparatively slow moving.

For pretty much everything else, Vesta can do as good or better. The Vesta can shield tank, but you might need to be more active on your abilities to keep its hull in one piece. Though, the bubble shields from the three-piece bonus might be enough to give the Vesta good survivability even for a point-and-click gamer.

Wells is a neat toy from what I've seen, but I don't think it's worth the cost compared to the Vesta, unless they've gone down in exchange price pretty low.